There has been known a technology for enabling an image forming apparatus to execute positional deviation correction so as to prevent a positional deviation of an image. In the positional deviation correction, a pattern image for positional deviation correction configured by a plurality of marks is formed on a belt member for sheet conveyance, each of the marks is detected by a sensor and a deviation value is calculated on the basis of a detection result. When forming an image of a printing target, a position of the image is adjusted on the basis of a correction value corresponding to the deviation value.
As an example of the technology relating to the positional deviation correction, there has been disclosed a technology in which N marks are formed to calculate a deviation value and when a deviation value based on the (N−1) marks is smaller than a threshold value, a number of marks of a pattern image to be formed next time is set to be (N−1) and a consumption amount of toner is thus suppressed.